This invention relates to sealing members, such as plug buttons and grommets. Both plug buttons and grommets are utilized to seal openings in panels and other structures (particularly in automobiles and other vehicles), while grommets are also used to position, support and seal various members, such as wires, conduits, cables, rods, or the like, that extend through such panels. As a grommet, one embodiment of the present invention is an improvement over the grommet constructions shown in U.S. Pat. Nos. 3,182,119 and 3,654,382.
U.S. Pat. No. 3,182,119 discloses a grommet construction having an elastomeric outer body and a base member formed of a ring of non-elastomeric (metal) material embedded in the elastomeric body. A plurality of resilient fingers are formed on the base member and project axially from one side of the elastomeric body. One of the fingers is shaped in the form of a hook to engage the edge of an opening in a panel, and the other fingers are shaped in the form of spring members having portions shaped to resiliently snap by and engage the edge of the opening in a panel to pull the contacting surface of the elastomeric body into sealing engagement with the surface of the panel surrounding the opening. Thus, to mount this grommet in a panel opening, the hooked finger is first positioned over the edge of the panel opening and the grommet is then pushed against the panel until the spring fingers snap into engagement with the edge of the panel opening. The grommet can be removed from the panel when an axial force is applied to the grommet sufficient to overcome the spring force of the fingers to cause them to be resiliently disengaged from the edge of the opening.
U.S. Pat. No. 3,654,382 discloses another grommet construction having an elastomeric body with a base member embedded therein, the base member being a ring of non-elastomeric material (metal). A plurality of fingers having locking tangs struck therefrom are formed on the base member and project axially from one side of the elastomeric body. Each of the locking tangs extends outwardly from its respective finger and projects away from the outer end of the respective finger toward the main portion of the elastomeric body. The grommet construction also has a recess formed therein and a peripheral sealing ridge formed on it and projecting from one side to seal it with the surface of the panel. The recess is formed in one side to seal it with the surface of the panel. The recess is formed in one side of the elastomeric body and surrounds an axially extending projection formed on one side of the elastomeric body. The axial projection has a hole in it for support of a wire, conduit, cable, rod, or the like, which is positioned in it when the grommet is utilized in practice. The recess allows the member to deflect radially in the grommet without substantial difficulty and yet maintain a tight seal around it. When the grommet shown in U.S. Pat. No. 3,654,382 is mounted in a panel opening, the grommet is pushed axially toward the opening so that the fingers are inserted into it. Axial force is utilized on the grommet construction until the free ends of the locking tangs clear the opening whereupon the tangs snap outwardly into engagement with the opposite side of the panel holding the grommet securely in place.
Numerous sealing members often referred to as plug buttons are known today. These plug buttons are typically comprised of a relatively soft (or elastomeric) material throughout so that they can be inserted easily in place. These known plug buttons can be easily removed by an axial force sufficient to overcome the retention force of the relatively soft material in the opening.
An object of the present invention is to provide improved sealing members which, as grommet constructions, are improvements over the constructions shown in U.S. Pat. Nos. 3,182,119 and 3,654,382 and which, as plug buttons, are improvements over known plug buttons made of a single relatively soft material.
A further object of the present invention is to provide improved grommet constructions which are less expensive and easier to manufacture than known grommets, and also are self-locking, lock at all points around the edge of an opening, seal the opening from all adverse elements, and can be installed properly in only one manner.
Still another object of the present invention is to provide improved "screw-on" and "split-type" grommet constructions which are improvements over known grommet constructions.
The foregoing and other objects are achieved according to the present invention by means of a sealing member having an annular portion made of a rigid material castably affixed to an elastomeric body. For use as a grommet, the sealing member has an opening in the center thereof and a projection situated around the opening for engaging a member to be supported and sealed thereby. The rigid annular shaped portion of the sealing member is slightly larger than the opening in which the member is to be positioned and the member has to be tilted or cocked in order to be inserted in the opening. Once the rigid annular portion is inserted beyond the edge of the opening, it securely locks the sealing member in place and prevents it from being easily removed from the opening. The grommet is locked at all points around the edge of the opening and also seals the opening entirely around its edge. A raised sealing ridge can also be provided on the outer periphery of the flexible elastomeric body to provide a secondary seal relative to the opening.
As another embodiment of grommet construction, the sealing member is adapted to be screwed onto a panel and seal an opening therein. A plurality of holes are provided in the rigid annular shaped portion for placement of the screws. With this embodiment, the rigid portion is not inserted through the opening to lock the grommet in place, but instead is utilized as a support for the screws as well as the flexible elastomeric body.
The sealing member also can have a thin slot or split formed in it (at least formed in the rigid annular shaped portion) so that large cables or bundles of wire and cables can be inserted more easily through it. The slot or split also allows the sealing member to be inserted more easily in openings. A deformable metal ring can be molded in the elastomeric portion of this "split-type" sealing member to assist in closing the member after the wires, cables, etc., are inserted in it. After it is deformed and the split closed, the metal ring assists in securely holding the member in its closed position.
Other objects, advantages and features of the invention will become apparent from the following description taken in conjunction with the accompanying drawings.